running after i turn it off.....?

Question

same guy with 75 c-20 350 chevy....

it was suggested to use better fuel.....
so what gas should i use? And i would have used the term dieseling but didnt know if that was a correct term or not.
Truck runs great ecept when i turn it off. Only does it once in a while.

will i need a regulaur timing light or adjustable?

and does anyone know the timing for tdc?
I dont have an rpm gauge so how will i know the rpms it sopposed to be at?

thanks guys

Paul thanks for the advice that sounds good i am gonna try it now. The idle is kinda high sounding, so i will try pouring this fluid in slowly and see what happens.

And another note i was told the silonoid in front of the throttle linkage is also sopposed to open and close? Mine doesnt move....

Answer 1

Just turn off the truck while it's still in gear and then shift to park as a temporary solution---probably have the idle set too high or the anti-dieseling solenoid on the carb is adjusted wrong or missing/inop. You should also try doing a combustion chamber cleaning--parts store have chemicals to use for this purpose or just pour -at a trickle- windshield washer solution down the carb while running at fast idle---1500 rpm's--- Washer solution---the regular blue stuff--- is mostly water and alchohol which will clean the carbon deposits out of the combustion chambers---just use about a quart or so and don't let the engine kill while doing it, will probably smoke a lot of white smoke for several minutes afterwards. Too much carbon deposits in the combustion chamber and idle set too high allows fuel mixture to still enter the combustion chamber and carbon deposits will stay hot, like glow plugs, to ignite the fuel---both conditions will cause run-on like what you've got. Timing may not be off if it's running ok otherwise but it might be good to check it to see if it's set to specs.

Answer 2

if you use an adjustable light you don't necessarily have to have a tach. just slowly rev it up until the timing quits going up on the scale should be no higher than 3000 rpm's. then set it to 36 - 38 degrees that should cure it. don't buy into whether it starts hard or not after it warms up.. if you are not comfortable with that set it at 8 btdc on the tab down by the harmonic balancer.

Answer 3

What causes "dieseling is too lean a mixture of air/fuel mixture. Usually, newer vehicles don't have this problem,so is your's a carburated engine? If so then just screw in the screws on the jets (one at a time) till the engine starts to stumble and back out 1 1/2 turns. This should take care of the problem.

Answer 4

What you have there is "run on" or deiseling, a problem with early pollution controled vehicles, you might have to use premium fuel to control it.

If it's running on, it also might be "pre igniting" (knock)a related problem that damages the engine under load.